This invention relates generally to agricultural rakes, and specifically to a locking mechanism for the height adjusting suspension system of a side delivery rake.
Side delivery rakes are generally well known in the agricultural industry as apparatus for consolidating swath-cut hay-type crops into windrows, or for turning windrows to promote more uniform drying. Most commonly, a single hay rake is pulled across the field behind a tractor, or other similar vehicle; however, with the use of a special hitch it is possible to arrange two or more rakes in tandem to decrease operation time.
The invention disclosed herein is primarily an improvement in a side delivery rake as shown, for example, in U.S. Pat. No. 2,781,626. With brief reference to FIGS. 1 and 2 of that patent, it can be seen that subframe S is supported below a main frame F and is adjustable in height relative thereto by, in part, rotatable rod 21 which through axial adjustment raises and lowers the aft end of the subframe. Crank 24 is manually rotated to effect the height adjustment. A compression spring 25 maintains the proper bias between the crank and a bearing 22, and also serves as a resilient suspension member for the subframe.
The problem with the rake described, and for which the instant invention supplies a solution, is that actual field operation affects the stability of the height adjustment setting. Initially, the crop engaging portion of the rake, depending from subframe S, is adjusted to the desired position relative to the ground by manipulation of crank 24. As the rake is moved across the field, the subframe is subjected to varying vertical forces related to field surface irregularity. The vertical forces are substantially absorbed by the spring 25; however, particularly under rough field conditions, there is a tendency for the crank 24 to be completely rotated and thus become misadjusted.